Residential Lighting: You designed the first Net Zero Energy residence in Chicago. What is a Net Zero Energy home?

Jonathan Boyer: It's a building that produces more energy than it consumes on an annual basis. It may have an excess of energy production in the summer and a deficit in the winter, breaking even in between. But, over the entire year, it produces more energy than it consumes.

RL: Tell us about the Yannell residence.

JB: It was completed in 2009 and received LEED Platinum. Getting LEED Platinum is very difficult, but it’s not as difficult as doing Net Zero Energy.

In the first year, we didn't quite hit Net Zero Energy. We missed it by about 10 percent. We discovered the solar thermal hot water panels were heating the water to temperatures in excess of 180 degrees, but we only needed 140. The excess energy was expelled into the atmosphere. We decided to take the excess energy and run it back into the geo-thermal wells in the backyard and save it. Then, we would take it in the hardest seasons in Chicago, which are January, February and March.

We also learned that the radiant floor system used to heat the main public areas of the house couldn’t heat quickly enough. To conserve energy during the day, we would get it down to maybe 60 degrees. Then, to get it back to 68 took more time than we originally had anticipated. So, we decided to keep the radiant heat at around 50 or 55 and use a water-to-air pump system attached to our geo-thermal to either cool the air in the summertime or heat it in the wintertime.

Those two measures saved an enormous amount of energy and brought us to the Net Zero Energy condition.

RL: How many square feet is the home?

JB: About 2,350.

RL: What can you tell us about the lighting systems?

JB: We used either compact fluorescents or LED lights. In 2009, there weren’t as many color temperature options available for LEDs. So, there were situations where LEDs didn’t really work and compact fluorescent gave better color rendition. We also used a variety of control systems.

RL: Is there room in a Net Zero Energy home for decorative fixtures?

JB: Quality of life is as important as energy consumption. That was one of the main factors in designing this house. There’s a lot of natural light, but there are also lights for pictures and artwork and for creating a variety of ambient conditions so that you have a pleasant experience at night and late afternoon. The combination of daylighting and reflective surfaces, a light-colored ceiling, for example, allowed us to put in decorative lighting. We have artwork that’s illuminated, and we have some outside lighting. There's indirect lighting that bathes the underside of the roofs. At night, the roof looks as if it’s floating or glows.

So, it wasn’t a Draconian solution where you had to eliminate all the lights and get it down to an absolute minimum. Certainly, we were careful – our watts per square foot was low. We worked with the client and Lightology offered advice. Under-cabinet strip LEDs were just coming out at the time. The virtue of LEDs over compact fluorescents is that you can use dimmers. So, you can tune the light quality in these spaces. The client responded positively to that.

RL: Is a Net Zero Energy home affordable versus a standard home?

JB: The cost of this house is over a million dollars. But, high-end homes in Chicago are in that range for this square footage. So, there’s no question, it’s more expensive than an average home, but it is in the norms of a high-end home in Chicago.